Camera crews descended on the ailing Sen. Edward M. Kennedy’s Hyannis compound this weekend to film an emotional tribute scheduled to air at the Democratic National Convention in August.

One source close to the senior senator said the roughly 15-minute film could be a sign that Kennedy, who is battling an aggressive form of brain cancer, won’t make the convention.

“The bulk of his treatment is completed, but he still gets chemo once a week. His immune system is still repressed, so right now his staff believes he won’t go,” said the source. “You never know with him, though. He might get up one day and decide he has to be there.”

The tribute will include clips of the Kennedy family throughout the years and feature the statesman and his wife, Vicki, said the source. It will be similar to the heart-wrenching 1968 convention tribute Charles Guggenheim compiled after Sen. Robert Kennedy was assassinated.

After that footage was aired, the convention hall in Chicago came to a standstill for 20 minutes.

“I think he’ll talk a little bit about how much this election means to him, and I think it will have a message about (Barack) Obama and about health care,” said the source, who hasn’t seen the film.

The tribute is expected to be aired during the four-day convention in Denver starting on Aug. 25, but sources were unsure exactly which day it would run.

Kennedy has been a strong Obama supporter since the begining of the Illinois Democrat’s race. Kennedy’s neice, Caroline, is part of a group helping Obama choose a vice president.

Obama, in a historic echo of Kennedy’s brother John, will accept the presidential nomination in a Denver football stadium outside the convention hall.

Kennedy is also girding up to return to work in September, according to two sources. It would be his first time back on the job at his Capitol Hill office since his surprise appearance to cast the deciding vote on a controversial Medicaid bill last month.

Kennedy was diagnosed with a cancerous brain tumor in May. He underwent surgery to remove the tumor and has been treated at Massachusetts General Hospital since.

Supporters, noting the Bay State senator’s mischievous love of surprise, cautioned that Kennedy may still show up at the Colorado convention – the 76-year-old was able to sail a leg of the famed Fugawi race off Cape Cod after he originally had called it off.